Halftone printing is a printing technique that simulates continuous tone using dots varying in size, shape and/or distribution.
Halftone techniques are widely used in color printing, combining different color screens. In order to avoid undesired moiré pattern artifacts, the screens are rotated in relation to each other. By varying the density of the four primary printing colors (cyan, magenta, yellow and black—CMYK) any desired shade may be reproduced. Commonly, the rotation angles are standardized angles, and as a result of these angles the dots of the different colors at a specific location on the print appear slightly shifted with respect to each other.
Different dot shapes may be used in halftone printing. Round dots are most common, but elliptical dots and square dots are also widely used.